Azo triphenylmethane dye.



'man Empire, residing,

ARTHUR I-IAUSDbRFER, 0F ELBERFELD, AND CARL HEIDENREICH, OF LEVERKUSEN GERMANY, ASSIGNORS T0 FARBENIFAB ELBERFELD, GERMANY, A CORPORATION OF RIKEN VORM. FRIEDR. BAYER & 00., 01"

GERMANY.

AZO TRIPHENYLMETHANE DYE.

Specification of Letters Patent.

Patented Jan. 3, 1911.

No Drawing. Original application filed May 24, 1910, Serial No. 533,045. Dividedand this application filed August 17, 1910. Serial No. 577,631.

To all whom it may concern: I

Be it known that we, ARTHUR Hansoonrnn and CARL HE DENREIoH,.citizens of the Gerrespectively at Elberfeld and Leverku'sen, near Cologne, Germany, have invented a the following is a specification. n

The present application which .is a divisional application of our application for Letters Patent Serial No. 563045, filed May 24th, 1910 relates to the production of a specific new azotriphenylmetha ne dyestufi' which can be chromed after dyeing. The process for its-production .consists in con densing ortho-chloro-m6ta-aminobenzaldehyde with two molecules of ortho-cresotinic acid, diazotizing the resulting leuco compound, combining the diazo compound with 1-phenyl-3-methyl 5-pyrazolone and oxidizing the leuco-azo dyestufl'.

The new dyestufi'is in the shape of the free carboxylic acid after being dried and pulverized a scarlet-red powder which is soluble in caustic soda lye with a reddish color and which is soluble .in concentrated sulfuric acid with a deep red color. The

dye thus obtained dyes woolfrom acid baths yellow shades, green shades fast to potting being obtained on chroming.

In order to illustrate the new process more fully the following example is given, the parts being by weight:-90 parts of the leuco compound obtained from one molecule of ortho-chloro-meta-aminobenzaldehyde and two molecules of orthocresotinic acid are stirred up with 1000 parts of water, 30 parts of calcined sodium carbonate are added to obtain a solution and the leuco compound is precipitated again by adding a mixture of 125 parts of hydrochloric acid 19 B. and 500 parts of ice. It is thendiazotized by means of a solution of 13.8 parts of sodium nitrite in water at a temperature of 510 C. The diazo compound thus obtained is introduced into a well cooled solution of 37 parts, of 1-phenyl-3.-methyl-5-pyrazolone in 600 parts of water and 29 parts of a 30 per cent. caustic sodalyeand 50 parts of calcined sodium carbonate, while the solution is stirred until the combination New Dye, of which.

yellowish-brown coloration.

is complete. When the separation of the sodium salt of the azo dyestuft' is complete,

the mass is filtered 01? and dried. The and compound is dried and 140 parts of it are dissolved in- 600 parts of concentrated sulfuric acid and to this solution whilebeing stirred 14 parts of sodium nitrite in 200 parts of concentrated sulfuric acid are added. The mixture is then warmed to 50-60 C. until the quantity of the color does no longer increase. The dark red melt is poured onice, the precipitate is filtered ofi' -and dried. The new dye isa scarlet-red powder scarcely soluble in water and soluble in dilute-solutions of sodium carbonate with a It dyes wool from acid baths yellow shades which on being treated with bichromate change'into a brlght yellowish-green fast to tolling, potting and light.

e claim': I j

The herein described new dyestufi' obtainable by reacting with the diazo compound of the triphenylmethane leuco compound derived from ortho--chloro-meta-amino-benz'aldehyde and ortho-cresotinic acid upon 1- phenyl-3-methyl-5-pyrazolone and oxidizing the leuco compound, Which'dyestuif is in the shape ofthefree carboxylic acid after being dried and pulverized a scarlet-red powder scarcely soluble ini-water and soluble in dilute solutions of sodium carbonate with a yellowish-brown coloration; dyeing wool,

from acid baths yellow shades which on being treated with bichromate change into a bright yellowish-green fast to fulling, potting and light,'substantially as described.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

- ARTHUR HAUSDGRFER. CARL HEIDENREIOH. 

